libx/image/ximage.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2007  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <libx/base.h>
  20 #include <libx/image.h>
  21 #include <stdio.h>
  22 #include <fcntl.h>
  23 #include <stdlib.h>
  24
  25 xbitmap *ximage_open (const char *filename)
  26 {
  27         int fd = open (filename, O_RDONLY);
  28
  29         if (!fd)
  30                 return 0;
  31
  32         unsigned char *header = (unsigned char *) malloc (sizeof (unsigned char) * 1080);
  33
  34         if (!header)
  35                 return 0;
  36
  37         int len = read (fd, header, 1078);
  38
  39         if (!len)
  40                 return 0;
  41
  42         if (header[0] != 'B' && header[1] != 'M')
  43                 return 0;
  44
  45         /* read in the width and height of the image, and the
  46                 number of colors used; ignore the rest */
  47         xbitmap *bitmap = (xbitmap *) malloc (sizeof (xbitmap));
  48         if (!bitmap)
  49                 return 0;
  50
  51         bitmap->width = header[18] | (header[19] << 8);
  52         bitmap->height = header[22] | (header[23] << 8);
  53         unsigned short num_colors = header[46] | (header[47] << 8);
  54
  55         /* assume we are working with an 8-bit file */
  56         if (num_colors == 0)
  57                 num_colors = 256;
  58
  59         bitmap->data = (unsigned char *) malloc (sizeof (unsigned char) * (bitmap->width * bitmap->height));
  60
  61         if (!bitmap->data)
  62                 return 0;
  63
  64         len = read (fd, bitmap->data, (bitmap->width * bitmap->height));
  65
  66         return bitmap;
  67 }
  68
  69 void ximage_draw (xbitmap *bitmap, unsigned x, unsigned y, int transparency)
  70 {
  71         unsigned a = 0;
  72         unsigned b = 0;
  73         unsigned j = 0;
  74
  75         if (transparency == -1) {
  76                 for(a = 0; a < (unsigned) bitmap->height * (unsigned) bitmap->width; a ++) {
  77                         if (j >= (unsigned) bitmap->width) {
  78                                 j = 0;
  79                                 b ++;
  80                         }
  81                         xpixel (j+x, b+y, bitmap->data[a]);
  82                         j ++;
  83                 }
  84         } else {
  85                 for(a = 0; a < (unsigned) bitmap->height * (unsigned) bitmap->width; a ++) {
  86                         if (j >= bitmap->width) {
  87                                 j = 0;
  88                                 b ++;
  89                         }
  90
  91                         if (bitmap->data[a] != (unsigned char) transparency)
  92                                 xpixel (j+x, b+y, bitmap->data[a]);
  93
  94                         j ++;
  95                 }
  96         }
  97 }
  98
  99 void ximage_draw_spec (xbitmap *bitmap, unsigned x, unsigned y, unsigned size_x, unsigned size_y, unsigned offset_x, unsigned offset_y, int transparency)
 100 {
 101         unsigned a = 0;
 102         unsigned b = 0;
 103         unsigned j = 0;
 104         unsigned k = ((offset_y*2) * size_x + offset_x);
 105
 106         if (transparency == -1) {
 107                 for(a = 0; a < size_x * size_y; a ++) {
 108                         if (j >= size_x) {
 109                                 j = 0;
 110                                 b ++;
 111                                 a += bitmap->width - size_x;
 112                         }
 113                         xpixel (j+x, b+y, bitmap->data[a+k]);
 114                         j ++;
 115                 }
 116         } else {
 117                 for(a = 0; a < (unsigned) bitmap->height * (unsigned) bitmap->width; a ++) {
 118                         if (j >= size_x) {
 119                                 j = 0;
 120                                 b ++;
 121
 122                                 if (b >= size_y)
 123                                         return;
 124
 125                                 a += bitmap->width - size_x;
 126                         }
 127
 128                         if (bitmap->data[a+k] != (unsigned char) transparency)
 129                                 xpixel (j+x, b+y, bitmap->data[a+k]);
 130
 131                         j ++;
 132                 }
 133         }
 134 }